Study design

Study 2

The second study was undertaken as a split-split-plot design to determine effects of temperature and packaging on the storage quality of the corms. One cold room (12⁰C) and one store room (ambient temperature) were available for the experiment. Corms harvested from the planting in October at Ukulinga were used.

Twenty four corms were collected from each sub-plot in Study 1 and the three replicated sub-plots for the same landrace x fertiliser level combined together to give a total of 72 corms per group. Eighteen boxes were obtained in order to provide three replicates for the experiment. Polyethylene bags were put into six of them, mesh bags put into six others and the remaining six were left empty. Groups of four corms from each landrace x fertiliser level combination were laid in each box in a predetermined factorial design for each of the six boxes (as shown for replicate 1) and the group labeled. Nine boxes (three with a polyethylene bag, three with a mesh bag and three without either) were placed in the cold room. The other nine boxes were put into the store room.

One corm from each group within each box was removed each month over a period of four months. The corm was cut in half; one half was peeled and freeze dried for starch and sugar analysis while the other half was used for determination of specific gravity and dry matter content.

The numbers of corms that showed signs of shoots or roots sprouting were also counted each month.